Voc. Chapter 2
is the volume of water passing along a river’s channel over a given period.
River discharge
The river channel shape is constantly adjusting to changes in inputs of water and material, so that it can transfer the water and material downstream. This constantly adjusting balance we call ...
Dynamic Equilibrium
What is the formula for finding the Cross sectional are?
Cross sectional area = width * mean depth
is caused by what is on the river’s bed and banks
Friction
How might the channel depth change if discharge increases?
The channel will get deeper as discharge increases (to a certain extent)
is just used to plot a river’s discharge during one single storm event.
flood or storm hydrograph
horizontal movement of water parallel to the river bed (very rare)
Laminar flow
Formula for Hydraulic Radius
Cross sectional area/wetted perimeter
How might velocity change if gradient changes?
If gradient is steeper = higher velocity
If gradient is gentler = lower velocity
Channel roughness causes , ______ which slows down the velocity of the water.
friction
A river regime is known as a ____________if it is based on one river with a single peak in the year.
simple regime
a series of eddies (swirls) both vertical and horizontal in a downstream direction (most common)
Turbulent flow
What is the formula for Velocity?
Velocity= Hydraulic radius x Gradient/ roughness (n)
If channel width and depth increase then what will happen to cross-sectional area?
If width and depth increase then so will cross-sectional area
____________ flow causes the most erosion
Turbulent
plots the change in river discharge over a year in cubic meters.
annual hydrograph
The force of air and water on the sides of river beds and banks
Hydraulic radius
Formula for finding discharge
In other words – Q = A x V
Q = discharge, A = cross –sectional area, V = velocity
Some of a river's energy has to be used to overcome _______, so it is not always efficient.
friction
Manning (an engineer) worked out that water in channels has different energy and efficiency depending on what?
-how rough the channel is
A river regime is known as a __________ if it is based on a river with lots of tributaries, which flow through a variety of climates and environments.
complex regime
The wearing away of beds and banks by the load carried by the river
abrasion
formed through the deposition of sediment and the subsequent compression as additional layer are deposited above. They are often porous.
sedimentary
The efficiency of a river channel = what?
a measure of the ability of a river channel to move water and sediment.
A river’s energy is used to erode it’s beds and banks and what?
transport material downstream